Refrigeration



Nov. 12, 1929. J. G. BERGDOLL REFRIGERATION Filed Feb. '7 1928 3wuewtoa UNET JOHN G. BEBGDOLL, OF YORK, PENNSYL'VANIA, ASSIGNOR T YORK ICE MACEINERY CORPRATION, OF YORK, PENNSYLVANIA, A GORPOBATIOI\T UTE DELA'WARE Application flle February 7, 1928. Serial N0. 252,493.

This invention relates to refrigeration und particularly to means for almost 1nstantl arresting, and as quickly resuming at Wi1 the refrigerative action of a direct expansion refrigerator. Certain features of the invention are applicable t0 indirect (brine circulation) Systems to accomplish a. similar result.

In the manufacture of ice cream it is important 110 arrest active refrigeration at the time the so-called swell commences, und under commercial conditions the refrigerative action is so intense that this arrest must be virtually instantaneous.

Prior to my invention it has beep proosed to eflect this result by displacmg the liquid refrigerant from the jackets of ice cream freezers by admitting gas under. pressure to the top of the jacket.- This scheme is particularly useful with direct expansiun s stems but has been successfully used m .slightly modified form with indirect systems.

In the prior art as a pli ed to direct expansion hot gas is taken oni the high pressure gas line betweebn the compresisor und couclenser und is admitted in the evaporator 'through a'n adjustably loaded reducing yalve at a pressure higher than suction ptessure, und so chosen as to corr'espond to the desimd free'zet temperature. At the same time the suction connection to the evaporator is closed. The effect is to displace-liquid refrigerant from the evaporator,-the refrigerant flowing back through the supply line 130 a, reservoir, such as a receiver suctio1i trap. An automatic valve closes to prevent back flow of gaseous refrigerant whe1i the liquid refrigerant hasbeen displaced. The prior arrangement though entirely operative involved two characteristics subject to improvem6ntf the discharge and return flow was not as rapid as was desired unless unduly large piping b e used, und. the displacement cf hqmdihto the receiver suctpion trap raised' the liquid level therein und other freezcrsl unduly, should several freez'ers be shut d0wn simultaneously.

- The present invntion ofiers improvement inthese respects und simplifies the structure, by providing adjacent each freezer a local reservoir into which its refrigegantmg be rapidly displaced without disturbing efl'cct 011 other fre'ezers conn ected 120 the same line. This greatly accelerates the displacement und also the subsequent return of the refrigerant and does away with the need for anyautomatic valve, closing against gas flcw.

Preferred embodiments cf ehe invention are illustrated in the accompanying drawing which is largely diagrammatic und which shows three freeze rs in vertical transverse section and other arts in vertical axial section with connecting piping und valves chiefly in elevation.

A liquid refrige rant feed line 1 leads from any suitable source cf volatile liquid refrigerant such as a high pressure receiver (not shown). This line discha1ges through a, valve 2 controlled by'a float 3 intc a receiver suction trap 4 in which a constant level of liquid refrigerant is 'maintained by the action cf the float and valve. 5 is a suction line to the compressor. The parts just described are illustrated as one known arrangement for maintaining the desired approximately constant level of liquid refri-gerant in the freezers to be described. Any equivalent Illig'ht be substituted.

Leading fromthe bottom oftrap 4 is the liquid refrigerant supply manifold 6'from which lead branch'pipes 7 to the jackets 8 of three identical ice cream freezers diiferentiabed by the letters A, B und O Any number mi ht be similarly connected. The central cy indrical space 9 of each freezer receives the mixture to be frozen and in practice would contai1i the' usual dasher (not shown) The freezers conform to established practice in their structural demils and parts not concerned with the present invention have been omitisedfrom the drawirig.

In each brauch 7 is a stop valve 11, und a check valve 12 permitting flow toward the jacket 8 and resisting reverse flow. Leading from each brauch 7 between its check v'alve 12 und. jacket 8 is a brauch pipe 13 which com- 95 municates with the lower end cf a corresponding closed chamber 14 each of greater volume than the relaflad jacket 8. Each chamber 14 has an oil drain connection controlled by a normally closed valve 15.

p1essor and condenser (not shown).

Connected with the top of trap 4 is e suction manifold 16. A bot gas manifold 17 leads from the high pressure gas line (not shown) say from a point between the com- Any suitable source cf refrigerant under pressure materially higher than suction pressure might be used.

The manifold 16 communicates loy branches 18, and the manifold 17 by branches 19, with two ports cf three-way valves 21, each 01 Which has e connection 22 with the jacket 8 of a corresponding freezer. The valves 21 are conventionally shown es having a porced plug 23 end handle 24, but m1y kuown arrangement which would connect branches 18 and 19 to connection 22, alteruately with euch other, might be substituted.

Brauch 18 is controlled lby a normally opcu stop valve 25 and brauch 19 by a normally open sfcop cock 26. 111 the brauch 19 there is also an adjustable pressure reducing valve 27. Any suitalole valve for reducing 1bhe pressure o i refrigerant passinp; the valve might be used. A simple spring-loaded valve is illustranted, the spring loading being adjusfialole' by turning handle 28.

A minor modification is illustrated es to ireezer C consistiug cf a brauch 31 leading from brauch 19 130 the top cf chamloer 14 and coutrolled by a needle valve 32 which is normally cracked, i. e. slightly open to loleed high pressure refrigerant with pressure reduction irrte the hop cf chamber 14. In a commercial installmtion all the chambers 14 ordinarily would be conriected alilre, i. e.,

1bhey Would all have or all omil: the brauch y 31 sind valve 32.

In operation valves 15 are closed, va1ves 11, 25 und 26 are open und valves 27 ere sei to establish on their outlet sides a pressure corresponding to the temperature it is desired to maintain in the freezers during the swell period. Duiing freezing handle 24 is thrown to the left (es shown on freezers A a:nd C). This connects the freezers (the active ones in parallel with each other) in the expansion portion of the refrigerant circuit. Liquid refrigerant fills the jacket 8 to the level est1blished in trap 4 and boiling ofi' through the suction connections 22, 18,16, 5produces the desiredheat abstraction.

4When the swell commences and it isvalve 27 assur es the maintenance cf a suitable pressure anal hence a suitalole temperature at such times.

. T0 resume heat abstraction (usually with a new batch cf cream) the handle 24 i's shifted to the left. The pressure in 14 aloove the liquid refrigerant forces this back into the jacket against 'the suction pressure, almost instantly, and much more ra'pidly than flow Would occur by gravity flow from trap 4 -as in the prior ert'.

H connection- 31 .a'nd valve 32 loe used its function is merely to maintaiu a slightly elevated pressure in the top cf charmber 14. This is' not essentiell. The leakage of heat to drum 14 and the resulting evaporation of a, small amount of liquid refrigeraut ther in is suflicient 130 prevent the accumulatiou of liquid refirigerant in drum 14 during thc active refrigerating Periods aud to generate the necessary expelling pressure.

As has heen suggested the invention may be applied in somewhat modified form to indirect systems, i. e. to briue circulation systems. 111 such cese the parts 1 130 5' iuclusive would be omitted. Mauifold 6 Would become the cold brine supply manifold from a brin'e cooler, manifold 16 Would hecome the lorine return manifold leadiug back to lzhe hrine cooler. Manifold 17 would become a compressed gas (usully air) line. Valve 27 would not be ueeded. In such an errangement shifting cf valve handle 24 would coutrol th'e displacement of brine from the cooler by compressed air fed from manifold 17 and its return linder pressure of air trapped in chamloer 14 above -the brine. The coui1econ 31 and valve 32 could be used, but in such cese the valve 32 would ordinarily be closed aud would loe opened oo accelerate refiux to the freezer jacket.

The dreiwing is illustrative only .and various modifications are obviously 130ssible. For

example, the flow precluding function of the Check valve 12 is not indispensable. There should be, for best results, such resistance to back flow as Will create a bias in favor cf flow co the chamloer 14, but experience has shown that moderate leakage ab a check valve 12 d0es not defeat operation.

What is claimed is 1. The combination of a cooler; a connection for supplying a cooling liquid thereto; a 'discharge connection leading -therefrom; a

'connection for supplying a liquid displacing gas to said cooler; means for opening either the discharge connection orthe displacing gas connection, while maintainiixg the other closed; a chamber having means for yieldingly resisting the entrance of liquid; means 'for resisting back flow through seid supply connection; and a connection from the lower portion 015 tl1e cooler to seid chamher.

2. The combination of a cooler; a conne0- tion for supplying a cooling liquid thercto; a discharge connection leading therefrom; a

connectionfor supplying a liq;1id displacing gas to said cooler; me'ans for opening either the discharge connction or the displacing gas connection, while maintaining the other closecl; a chamber in which a compressible 'medium is traPped; a connection from r1e -tion from the lower portion of the evaporator to saicl chambet; and Ineans for 'resisting back flovv through said supply connection.

4:. The combination of an evaporator cooler; n a connection for supplying volatile liquid ref1igerant thereto; a suction connection leading therefrom; a connection for supplying gaseous refrigerant thereto at a pressure higher than suction Pressure; meanS for opening either the suction connection o1 the high pressure gas conneetion while maintaining the other closed; a, chamber oontaining traPpecl gaseous refrigerant; a connection from the lovver portion of the evaporator to said chamber; and a check valve in the supply connection.

5. The combination f an evaporator cooler; a connection for supplying volatile liquid refrigerant thereto; a suction conneetion leading therefrom; a connect1on for supplying gaseous refrigerant thereto at a pressure higher than suction pressure; means for opening eithenthe suction connection 01 thehigh pressure gas connection, While maintgmining the otl1er closed;. a, closed chamber adjacent said cooler; a bleed connection from seid high pressure gaskaous refrigefant connection 1:0 said chamber; a connection from the lower portion of the evaporator to.the lower ortion of said chamber; and means fo r resisting back flo.w through seid supply connection.

In testimony whereof I have signed my name to this specification.

JOHN o. BERGDOLL. 

